U.S. patent application number 13/428812 was filed with the patent office on 2013-09-26 for activate es cell for particular ue(s).
This patent application is currently assigned to Nokia Siemens Networks Oy. The applicant listed for this patent is Michael Joseph BACH. Invention is credited to Michael Joseph BACH.
Application Number | 20130252660 13/428812 |
Document ID | / |
Family ID | 47891665 |
Filed Date | 2013-09-26 |
United States Patent
Application |
20130252660 |
Kind Code |
A1 |
BACH; Michael Joseph |
September 26, 2013 |
ACTIVATE ES CELL FOR PARTICULAR UE(S)
Abstract
A method includes determining, at a first cell and for a
selected user equipment, a second cell would have a better
performing RF interface connection with the selected user equipment
than the selected user equipment currently has with the first cell.
The first cell can provide radio frequency coverage for the second
cell. The method includes sending to the second cell one or more
messages indicating the second cell should not enter or be in an
energy saving state at least while the selected user equipment or a
selected user application on the selected user equipment is
connected to the second cell. Another method includes determining a
cell should not enter an energy saving state at least while a
selected user equipment is connected to the cell; and the cell not
entering the energy saving state at least while the selected user
equipment is connected to the cell.
Inventors: |
BACH; Michael Joseph;
(Kildeer, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BACH; Michael Joseph |
Kildeer |
IL |
US |
|
|
Assignee: |
Nokia Siemens Networks Oy
|
Family ID: |
47891665 |
Appl. No.: |
13/428812 |
Filed: |
March 23, 2012 |
Current U.S.
Class: |
455/525 |
Current CPC
Class: |
H04W 36/0055 20130101;
H04W 36/0061 20130101; H04W 92/20 20130101; H04W 52/0206 20130101;
H04W 48/18 20130101; H04W 84/045 20130101; H04W 52/0277 20130101;
H04W 36/24 20130101; Y02D 30/70 20200801 |
Class at
Publication: |
455/525 |
International
Class: |
H04W 36/30 20090101
H04W036/30 |
Claims
1. A method, comprising: determining, at a first cell and for a
selected user equipment, a second cell would have a better
performing radio frequency interface connection with the selected
user equipment than the selected user equipment currently has with
the first cell, wherein the first cell can provide radio frequency
coverage for the second cell; and sending to the second cell one or
more messages comprising one or more instructions the second cell
should not enter or be in an energy saving state at least while the
selected user equipment or a selected user application on the
selected user equipment is connected to the second cell, the
sending responsive to a determination the second cell would have a
better performing radio frequency interface connection with the
selected user equipment than the selected user equipment currently
has with the first cell.
2. The method of claim 1, wherein the one or more messages comprise
a handover request message comprising the instruction the second
cell should not enter an energy saving state at least while the
selected user equipment is connected to the second cell.
3. The method of claim 1, wherein the second cell is in an energy
saving state when the determining is performed and wherein the one
or more messages further comprises an instruction for the second
cell to activate itself.
4-5. (canceled)
6. The method of claim 1, wherein the selected user application on
the selected user equipment is connected to the second cell at
least while a radio access bearer for the user application is
active and not released.
7. The method of claim 1, wherein the selected user equipment is
connected to the second cell until the second cell hands the
selected user equipment over to another cell.
8. The method of claim 1, wherein determining further comprises
determining the selected user equipment is in or is expected to
enter a coverage area of the second cell and determining the
selected user equipment or quality of the radio frequency coverage
for the selected user application meets one or more criteria, and,
responsive to a determination the selected user equipment or the
quality of the radio frequency coverage for the selected user
application meet one or more criteria, determining the second cell
would have the better performing radio frequency interface
connection with the selected user equipment than the selected user
equipment currently has with the first cell.
9. The method of claim 8, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprises determining one or more particular radio access bearer
configurations are associated with the selected user application,
wherein the one or more radio access bearer configurations have one
or more particular values of one or both of quality of service
class identifiers or quality of service, and based on the
determination of the one or more particular radio access bearer
configurations, determining the second cell would have the better
performing radio frequency interface connection with the selected
user equipment than the selected user equipment currently has with
the first cell.
10. The method of claim 8, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprises determining a certain threshold is met for an average
power headroom level, reported by the selected user equipment, for
a time duration.
11. (canceled)
12. The method of claim 8, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprises determining an average rank indicator for multiple-input,
multiple output for a time duration for the selected user equipment
meets a certain threshold.
13. (canceled)
14. The method of claim 8, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprises determining channel quality indication indices for the
selected user equipment for a time duration meets a certain
threshold.
15-17. (canceled)
18. A method, comprising: determining a cell should not enter an
energy saving state at least while a selected user equipment is
connected to the cell; and the cell not entering the energy saving
state at least while the selected user equipment is connected to
the cell.
19. The method of claim 17, wherein the cell is a first cell, and
wherein the determining further comprises determining, based on one
or more messages received from a second cell comprising an
instruction that the first cell should not enter the energy saving
state at least while the selected user equipment is connected to
the first cell, that the first cell should not enter the energy
saving state at least while the selected user equipment is
connected to the first cell.
20. The method of claim 18, wherein the one or more messages
comprise a handover request message comprising an instruction the
first cell should not enter an energy saving state at least while
the selected user equipment is connected to the first cell.
21. The method of claim 18, wherein the first cell is in an energy
saving state when receiving at least one of the one or more
messages, wherein the one or more messages further comprise an
instruction for the first cell to activate itself, and wherein the
first cell, responsive to the instruction for the first cell to
activate itself, transitions from the energy saving state to an
active state.
22-23. (canceled)
24. The method of claim 17, wherein determining further comprises
determining the selected user equipment or quality of radio
frequency coverage for a selected user application on the selected
user equipment meets one or more criteria, and, responsive to a
determination the selected user equipment or the quality of the
radio frequency the cell should not enter an energy saving state at
least while the selected user equipment or the selected user
application is connected to the cell.
25. (canceled)
26. The method of claim 24, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprises determining a certain threshold is met for an average
power headroom level, reported by the selected user equipment, for
a time duration.
27. (canceled)
28. The method of claim 24, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprises determining an average rank indicator for multiple-input,
multiple output for a time duration for the selected user equipment
meets a certain threshold.
29. The method of claim 24, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprises determining modulation and coding scheme indices for the
selected user equipment for a time duration meets a certain
threshold.
30. The method of claim 24, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprises determining channel quality indication indices for the
selected user equipment for a time duration meets a certain
threshold.
31. The method of claim 24, wherein determining the selected user
equipment or quality of the radio frequency coverage for the
selected user application meets one or more criteria further
comprise determining whether one or more of quality of service,
modulation and coding scheme indices, or bit rate values meet
certain criteria.
32-33. (canceled)
Description
TECHNICAL FIELD
[0001] This invention relates generally to wireless communications
and, more specifically, relates to base stations and interaction of
the base stations with user equipment.
BACKGROUND
[0002] This section is intended to provide a background or context
to the invention disclosed below. The description herein may
include concepts that could be pursued, but are not necessarily
ones that have been previously conceived, implemented or described.
Therefore, unless otherwise explicitly indicated herein, what is
described in this section is not prior art to the description in
this application and is not admitted to be prior art by inclusion
in this section.
[0003] The following abbreviations that may be found in the
specification and/or the drawing figures are defined as
follows:
[0004] 3GPP third generation partnership project
[0005] AOA angle of arrival
[0006] AP access point
[0007] CQI channel quality indicator
[0008] DCA discontinuous carrier activation
[0009] DL downlink (from base station to UE)
[0010] EMS element management system
[0011] eNB or eNodeB evolved Node B (e.g., LTE base station)
[0012] E-RAB E-UTRAN radio access bearer
[0013] ES energy savings
[0014] E-UTRAN evolved UTRAN
[0015] GBR guaranteed bit rate
[0016] hetnet heterogeneous network
[0017] HO handover
[0018] ID identification
[0019] IE information element
[0020] LTE long term evolution
[0021] MCS modulation and coding scheme
[0022] MDT minimization of drive test
[0023] MIMO multiple input-multiple output
[0024] MME mobility management entity
[0025] NSN Nokia Siemens Networks
[0026] O&M operations and maintenance
[0027] PH power headroom
[0028] PRB physical resource block
[0029] QCI QoS class identifier
[0030] RACH random access channel
[0031] RAN radio access network
[0032] RAT radio access technology
[0033] Rel release
[0034] RF radio frequency
[0035] RI rank indicator
[0036] RLF radio link failure
[0037] RNL radio network layer
[0038] RSRP reference signal received power
[0039] RSRQ reference signal received quality
[0040] RRM radio resource management
[0041] RRC radio resource control
[0042] Rx reception or receiver
[0043] SINR signal to interference plus noise ratio
[0044] SRS sounding reference signal
[0045] TA time alignment
[0046] TS technical standard
[0047] TR technical report
[0048] Tx transmission or transmitter
[0049] UE user equipment
[0050] UL uplink (from UE to base station)
[0051] UTRAN universal terrestrial radio access network
[0052] QoS quality of service
[0053] An Energy Savings (ES) method via deactivating unneeded eNB
cell(s) has been a supported functionality in LTE since Rel-9. 3GPP
TS 36.423 V9.6.0 (2011-03), section 8.3.11 (Cell Activation)
provides stage 3 details for the X2 application protocol (X2AP)
including the Cell Activation procedure used to request to a
neighboring eNB to switch on one or more cells, previously reported
as inactive due to energy saving reasons. 3GPP TS 36.300 V11.0.0
(2011-12), provides the Overall E-UTRA and E-UTRAN description
where section 22.4.4.2 ("Solution description"), currently contains
the following text regarding support for Energy Savings:
[0054] "All informed eNBs maintain the cell configuration data also
when a certain cell is dormant. ENBs owning non-capacity boosting
cells may request a re-activation over the X2 interface if capacity
needs in such cells demand to do so. This is achieved via the Cell
Activation procedure."
[0055] Cell re-activation occurs when "capacity needs demand to do
so". But there may be other needs besides capacity needs at the
non-capacity boosting (e.g., coverage) cell that may demand
reactivation of a cell.
SUMMARY
[0056] This Summary is meant to be exemplary and illustrates
possible examples of implementations.
[0057] An exemplary embodiment is a method including determining,
at a first cell and for a selected user equipment, a second cell
would have a better performing radio frequency interface connection
with the selected user equipment than the selected user equipment
currently has with the first cell. The first cell can provide radio
frequency coverage for the second cell. The method includes sending
to the second cell one or more messages comprising one or more
instructions the second cell should not enter or be in an energy
saving state at least while the selected user equipment or a
selected user application on the selected user equipment is
connected to the second cell. The sending is responsive to a
determination the second cell would have a better performing radio
frequency interface connection with the selected user equipment
than the selected user equipment currently has with the first
cell.
[0058] In an additional exemplary embodiment, a computer program
product is disclosed that includes a computer-readable storage
medium bearing computer program code embodied therein for use with
a computer. The computer program code includes: code for
determining, at a first cell and for a selected user equipment, a
second cell would have a better performing radio frequency
interface connection with the selected user equipment than the
selected user equipment currently has with the first cell, wherein
the first cell can provide radio frequency coverage for the second
cell; and code for sending to the second cell one or more messages
comprising one or more instructions the second cell should not
enter or be in an energy saving state at least while the selected
user equipment or a selected user application on the selected user
equipment is connected to the second cell, the sending responsive
to a determination the second cell would have a better performing
radio frequency interface connection with the selected user
equipment than the selected user equipment currently has with the
first cell.
[0059] In another exemplary embodiment, an apparatus includes one
or more processors and one or more memories including computer
program code. The one or more memories and the computer program
code are configured, with the one or more processors, to cause the
apparatus to perform at least the following: determining, at a
first cell and for a selected user equipment, a second cell would
have a better performing radio frequency interface connection with
the selected user equipment than the selected user equipment
currently has with the first cell, wherein the first cell can
provide radio frequency coverage for the second cell; and sending
to the second cell one or more messages comprising one or more
instructions the second cell should not enter or be in an energy
saving state at least while the selected user equipment or a
selected user application on the selected user equipment is
connected to the second cell, the sending responsive to a
determination the second cell would have a better performing radio
frequency interface connection with the selected user equipment
than the selected user equipment currently has with the first
cell.
[0060] In a further exemplary embodiment, an apparatus is disclosed
that includes means for determining, at a first cell and for a
selected user equipment, a second cell would have a better
performing radio frequency interface connection with the selected
user equipment than the selected user equipment currently has with
the first cell, wherein the first cell can provide radio frequency
coverage for the second cell; and means for sending to the second
cell one or more messages comprising one or more instructions the
second cell should not enter or be in an energy saving state at
least while the selected user equipment or a selected user
application on the selected user equipment is connected to the
second cell, the sending responsive to a determination the second
cell would have a better performing radio frequency interface
connection with the selected user equipment than the selected user
equipment currently has with the first cell.
[0061] In another exemplary embodiment, a method is disclosed that
includes determining a cell should not enter an energy saving state
at least while a selected user equipment is connected to the cell;
and the cell not entering the energy saving state at least while
the selected user equipment is connected to the cell.
[0062] In an additional exemplary embodiment, a computer program
product is disclosed that includes a computer-readable storage
medium bearing computer program code embodied therein for use with
a computer. The computer program code includes: code for
determining a cell should not enter an energy saving state at least
while a selected user equipment is connected to the cell; and code
for the cell not entering the energy saving state at least while
the selected user equipment is connected to the cell.
[0063] In another exemplary embodiment, an apparatus includes one
or more processors and one or more memories including computer
program code. The one or more memories and the computer program
code are configured, with the one or more processors, to cause the
apparatus to perform at least the following: determining a cell
should not enter an energy saving state at least while a selected
user equipment is connected to the cell; and the cell not entering
the energy saving state at least while the selected user equipment
is connected to the cell.
[0064] In a further exemplary embodiment, an apparatus is disclosed
that includes means for determining a cell should not enter an
energy saving state at least while a selected user equipment is
connected to the cell; and code for causing the cell not to enter
the energy saving state at least while the selected user equipment
is connected to the cell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0065] In the attached Drawing Figures:
[0066] FIG. 1 illustrates a hetnet scenario;
[0067] FIG. 2 illustrates an exemplary system in which the
exemplary embodiments of the instant invention may be
practiced;
[0068] FIG. 3 is an example of a possible hetnet scenario;
[0069] FIG. 4 is a block diagram illustrating exemplary
interactions taken by a number of entities in a network in order to
activate an ES cell for particular UE(s);
[0070] FIG. 5 illustrates a table representing a number of IEs and
including a "Don't go Dormant" IE useful for exemplary embodiments
of the instant invention;
[0071] FIG. 6 illustrates a table of possible elements in a Cell
Activation Request message in accordance with an exemplary
embodiment;
[0072] FIG. 7 illustrates two tables for an Enable for UE IE, a
first table describing elements of the IE and a second table
describing a maxnoofUEs range;
[0073] FIG. 8 is a table of E-RAB Level QoS Parameters from section
9.2.1.15 of 3GPP TS 36.413 V10.4.0 (2011-12);
[0074] FIGS. 9 and 10 are each logic flow diagrams illustrating the
operation of a method, and a result of execution of computer
program instructions embodied on a computer readable memory, in
accordance with the exemplary embodiments of this invention;
and
[0075] FIG. 11 is a Power Headroom MAC control element from FIG.
6.1.2.6-1 of 3GPP TS 36.321 V10.5.0 (2012-03).
DETAILED DESCRIPTION OF THE DRAWINGS
[0076] As stated above, there may be other needs besides capacity
needs at the non-capacity boosting (e.g., coverage) cell that may
demand reactivation of a cell. 3GPP TR 36.927 V10.1.0 (2011-09)
states the following (see section 4):
[0077] "Energy saving solutions identified in this study item
should be justified by valid scenario(s), and based on cell/network
load situation. Impacts on legacy and new terminals when
introducing an energy saving solution should be carefully
considered. The scope of the study item shall be as follows: [0078]
User accessibility should be guaranteed when a cell transfers to
energy saving mode [0079] Backward compatibility and the ability to
provide energy saving for Rel-10 network deployment that serves a
number of legacy UEs [0080] Solutions shall not impact the Uu
physical layer [0081] The solutions should not impact negatively
the UE power consumption"
[0082] Taking the last quoted statement from TR 36.927 that "The
solutions should not impact negatively the UE power consumption",
consider a hetnet scenario such as that shown in FIG. 1. In this
example, the eNB 107 at the tower 109 creates the macro cell 106.
There are two active pico cells 105-1, 105-2, and one dormant pico
cell 105-3, each of which is formed by a corresponding eNB (e.g.,
an access point (AP)) 108. Each of the cells 105 and 106 has a
corresponding coverage area illustrated in the figure. The UE 110
is within the pico cell 105-3, but the cell 105-3 is dormant. It is
helpful at this point to provide a short description of
terminology. Depending on the 3GPP standard being examined, the
pico cell may be referred to as an "original" cell or a "capacity
booster" cell and the macro cell may be referred to as a
"candidate" cell or a "coverage" (or "covering") cell.
[0083] A typical hetnet environment has pico cells 105 deployed for
both capacity (e.g., hot spot) and coverage (e.g., dead spot)
reasons. In some places, e.g., a cell edge or in a building, a pico
cell may be added for both reasons. Pico cells 105 can also be
beneficial for improving bearer data rates. A prime advantage of
deploying pico cells is the deployment enables low Tx power for
nearby UEs 110, which reduces UE power usage and interference.
[0084] Given an ES enabled pico cell 105 and a UE 110 within the
normal coverage area of the pico cell 105 when activated as shown
in the diagram, if the ES enabled pico cell 105 goes dormant (as
shown by cell 105-3), then the UE 110 must connect to the macro
node antenna (e.g., 109) that can be a kilometer or more away, as
opposed to the ES pico cell 105-3 which is only, e.g., 50 meters
away (e.g., to the antenna of the capacity boosting cell 105-3).
The UE power consumption and transmit power will then be higher to
compensate for the additional propagation losses to achieve the
necessary SINR. While the increased power amount may not
significantly impact UE battery life using some user applications,
if the UE 110 requires a high volume and rate of uplink traffic
while running other types of user applications (e.g., video), then
a significant negative impact on UE power consumption is to be
expected with the nearby node 105-3 deactivated. Therefore, the
pico eNB 108-3 may need to be re-activated to meet UE battery
savings needs, as well as for macro capacity needs since the ES
solution should not impact negatively UE power consumption.
Degradation of UE QoS may also arise due to the differences in the
uplink signal path between transmitting to the nearby pico cell 105
or a distant macro cell 106. Furthermore, inter-RAT scenarios may
require a legacy RAT node to reactivate a dormant LTE node when a
user requires high speed data or LTE only capable services.
[0085] Thus, there is a need for activating via eNB interfaces a
dormant cell besides for capacity needs, namely for some UE
power/data reasons or other needs in accordance with the scope
given in TR 36.927.
[0086] Furthermore, there is a need for a cell not to go dormant
for ES reasons even if the average cell load is low enough such
that the load would trigger the cell to do so per conventional
systems due to some UE power/data reasons.
[0087] These needs are met by exemplary embodiments of the instant
invention. In one aspect of the invention, methods, apparatus, and
program products are presented for activating dormant ES cells for
particular UE(s).
[0088] Before proceeding with additional description regarding
activating dormant ES cells for particular UE(s), reference is made
to FIG. 2, which illustrates an exemplary system in which the
exemplary embodiments of the instant invention may be practiced. In
FIG. 2, a user equipment (UE) 110 is in wireless communication with
a network 100 via one of the wireless links 115-1 (with eNB 107) or
the wireless link 115-2 (with pico eNB 108), where the wireless
links 115 can implement a Uu interface. The user equipment 110
includes one or more processors 120, one or more memories 125, and
one or more transceivers 130 interconnected through one or more
buses 127. The one or more transceivers 130 are connected to one or
more antennas 128. The one or more memories 125 include computer
program code 123. The one or more memories 125 and the computer
program code 123 are configured to, with the one or more processors
120, cause the user equipment 110 to perform one or more of the
operations as described herein.
[0089] The network 100 includes eNB 107, eNB 108, and O&M
system 191. In the examples presented herein, the eNB 107 forms the
coverage/candidate cell 106 (see FIG. 1) and the eNB 108 forms the
capacity booster/original cell 105 (see FIG. 1). The eNodeB 107
includes one or more processors 150, one or more memories 155, one
or more network interfaces (N/W I/F(s)) 161, and one or more
transceivers 160 (each comprising a transmitter, Tx, and a
receiver, Rx) interconnected through one or more buses 157. The one
or more transceivers 160 are connected to one or more antennas 158.
The one or more memories 155 include computer program code 153. The
one or more memories 155 and the computer program code 153 are
configured to, with the one or more processors 150, cause the
eNodeB 107 to perform one or more of the operations as described
herein. The one or more network interfaces 161 communicate over
networks such as the networks 173, 175.
[0090] The eNB 108 includes one or more processors 172, one or more
memories 136, one or more network interfaces (N/W I/F(s)) 139, and
one or more transceivers 138 (each comprising a transmitter, Tx,
and a receiver, Rx) interconnected through one or more buses 140.
The one or more transceivers 160 are connected to one or more
antennas 145. The one or more memories 136 include computer program
code 137. The one or more memories 136 and the computer program
code 137 are configured to, with the one or more processors 172,
cause the eNB 108 to perform one or more of the operations as
described herein. The one or more network interfaces 139
communicate over networks such as the networks 173, 175.
[0091] The O&M system 191 includes one or more processors 180,
one or more memories 195, and one or more network interfaces (N/W
I/F(s)) 190 interconnected through one or more buses 187. The one
or more memories 195 include computer program code 197. The one or
more memories 195 and the computer program code 197 are configured
to, with the one or more processors 180, cause the O&M system
191 to perform one or more of the operations as described herein.
The one or more network interfaces 190 communicate over networks
such as the networks 173, 175.
[0092] The eNodeB 107 and the eNB 108 communicate using, e.g.,
network 173. The network 173 may be wired or wireless or both and
may implement, e.g., an X2 interface (see, e.g., 3GPP TS 36.423
V11.0.0 (2012-03)). The O&M system uses the network 175 to
communicate with the eNodeB 107 and eNB 108. The network 175 may be
wired or wireless or both and may implement, e.g., an Itf-S
interface.
[0093] The computer readable memories 136, 155, and 195 may be of
any type suitable to the local technical environment and may be
implemented using any suitable data storage technology, such as
semiconductor based memory devices, flash memory, magnetic memory
devices and systems, optical memory devices and systems, fixed
memory and removable memory. The processors 150, 172, and 180 may
be of any type suitable to the local technical environment, and may
include one or more of general purpose computers, special purpose
computers, microprocessors, digital signal processors (DSPs) and
processors based on a multi-core processor architecture, as
non-limiting examples.
[0094] As stated above, exemplary embodiments of the instant
invention concern activating dormant ES cells for particular UE(s).
Referring to FIG. 3, an example of a possible hetnet scenario is
shown. Cells A and B are coverage cells, and cells C, D, E, F, and
G are capacity booster cells. In this example, cell A provides
coverage for cells C, D, and E, and cell B provides coverage for
cells E, F, and G. 3GPP RAN3 has had the following Energy Saving
application scenario since Rel-9:
[0095] Where capacity booster cell(s) (e.g., a cell such as cell C)
can turn off given their traffic load is under a switch-off
threshold and coverage cell (cell A) is under a configured
switch-off threshold for time duration in order to optimize energy
consumption. Neighbors are notified via the Deactivation Indication
IE in the X2AP: ENB Configuration Update message.
[0096] As macro coverage cell A exceeds a configured traffic
switch-on threshold for a given duration, cell A may send an
X2:Cell Activation Request message to dormant cell(s) to switch-on.
TR 36.927 indicates that an ES should not impact negatively UE
power consumption. An NSN study has concluded that a majority of
reported customer care issues are related to coverage or
quality.
[0097] 3GPP TS 32.762 V11.0.0 (2011-12) contains the following
terminology for the ES cells: "candidate cell is a cell which can
provide coverage when the original cell goes into Energy Saving
state." The following is a general high level ES process flow using
configured attribute terminology from SA5 (a telecom management
group within 3GPP):
[0098] 1) Original (e.g., capacity booster) cell esSwitch attribute
configured value is On;
[0099] 2) Original cell is ESCoveredBy attribute value configured
with Yes for at least one candidate (e.g., coverage) cell;
[0100] 3) Original cell load falls below thresholds (e.g.
esActivationOriginalCellLoadParameters,
esActivationCandidateCellLoadParameters) for a configured time
duration;
[0101] 4) Original cell offloads any remaining UEs via HO with RNL
cause set to Switch Off Ongoing;
[0102] 5) Original cell sends eNB Configuration Update message to
neighbors (Deactivation Indication IE included) and
deactivates;
[0103] 6) Candidate cell esDeactivationCandidateCellsLoadParameters
load surpasses threshold for time duration;
[0104] 7) Candidate cell sends Cell Activation Request message to
inactive Original cell;
[0105] 8) Original cell switches on cell and returns the Cell
Activation Response message; and
[0106] 9) Original cell informs neighbor cell(s) about the
re-activation via the eNB Configuration Update message
(Deactivation Indication IE, described below, not included).
[0107] Problems with current ES usage and corresponding quality
include the following. Currently the trigger for ES specified per
TS 32.522 is not tied to particular user(s), but rather is
threshold-based on total PRB load. UE(s) using apps such as high
rate UL video may consume significant UE battery life with a local
pico cell (e.g., capacity booster cell 105) off, while the pico
cell load for one UE falls under the traffic switch-off threshold
(e.g. esActivationOriginalCellLoadParameters), which is based on an
aggregate PRB percentage. So such a UE's battery life is degraded
in certain instances if ES is enabled. QoS may also be
degraded.
[0108] Exemplary embodiments of the instant invention correct these
problems. In an exemplary embodiment, a method of enabling better
targeting of energy saving techniques in a cellular network is
disclosed. A first (e.g., coverage) cell monitors allocated UEs for
any requiring high performance and/or having significant UE battery
usage (e.g., based on power headroom reporting as given in TS
36.321 section 5.4.6). The first cell detects a UE requiring high
performance and/or having significant UE battery usage. The first
cell also detects whether such UE(s) are in or are arriving into a
dormant second (e.g., capacity booster) cell coverage area, wherein
the dormant cell would provide better performance and/or UE battery
life to the UE than would the current first cell. In this exemplary
situation, the first cell sends, e.g., one or both of activation
and handover messages that indicate the second cell should be
activated and remain activated during at least the use of the user
application(s) of the UE(s) requiring better performance and/or UE
battery life.
[0109] In further exemplary embodiments, as part of a method of
activating a dormant cell to serve a UE requiring high RF
performance, possible triggers to be used by the first cell for
detecting UEs requiring high RF performance include the following:
particular QCI value(s) in the SlAP bearer setup procedures (see TS
36.413) for a UE, e.g., QCI values for user applications requiring
high bit rate, low latency such as real time gaming (QCI=3) and/or
live streaming video (QCI=2) and/or large values for GBR QoS
information as specified in TS 23.401.
[0110] After the first cell has detected UE(s) requiring and/or
using high performance software and/or having high battery usage
that are in or may arrive in a second cell coverage area, the first
cell includes UE information in a message (e.g. the X2: HANDOVER
REQUEST message) that indicates to the second cell receiving the UE
information in the message that the second cell should not hand the
UE back to the first eNB (forming the first cell) and deactivate
due to low overall load.
[0111] Exemplary methods for configuring eNB policy for going
dormant include the following non-limiting examples. An eNB can be
configured to include one or more of the following exemplary,
non-limiting attributes, which can then be used in determining
whether to turn on a dormant cell: 1) Cell load threshold(s) based
on individual UE uplink GBR E-RAB usage (e.g., add to 3GPP TS
32.522); 2) An attribute based on PRB usage; 3) duration time
(e.g., for the previously dormant cell to be active).
[0112] Determination of UE transmission cost in coverage (e.g.,
candidate) cell may be based on a UE performance metric composed of
one or more of the following parameters and their corresponding
limits: 1) power headroom (PH): low average; spatial multiplexing:
No; bit rate: high; and/or MCS: low average. Additional information
concerning these metrics are described below.
[0113] There are a number of techniques useful to detect if a UE is
entering or resides in the coverage area of a capacity booster cell
105: 1) internal mechanisms of the coverage eNB, e.g. TA/AOA
mechanisms; 2) probing, where the coverage cell activates pico
cell(s) for a brief time period to obtain UE measurements; 3) a
pico cell is in a discontinuous carrier activation mode; 4) UE
reports based, e.g., on satellite location systems; 5) Minimization
of drive testing (MDT); 6) UE measurement reports of other cells on
the same and/or different carriers; 7) requests to a positioning
server; and 8) combinations of the above.
[0114] Turning now to FIG. 4, this figure is a block diagram
illustrating exemplary interactions taken by a number of entities
in a network in order to activate an ES cell for particular UE(s).
The element management system (EMS) is typically a function
performed by O&M system 191, although this function may be
performed by other entities in the network 100. The EMS 405
operates to perform part of blocks 410 and 435. An eNB 108 that
forms the capacity booster cell 105 performs blocks 410, 415, 420,
425, 430, 480, 485, and 490. An eNB 107 that forms the coverage
cell 106 performs blocks 425, 435, 445, 450, 455, 460, 465, 470,
and 475. For simplicity, cells 105 and 106 are mainly referred
herein in reference to FIG. 4, but it is to be understood that the
corresponding eNBs 108, 107 (respectively) cause the operations in
the blocks to be performed.
[0115] The EMS 405 configures the capacity booster cell 105 in
block 410 with certain metrics (e.g., a threshold for individual UE
UL PRB usage, and/or Tx cost metric and duration, and/or power
headroom margin threshold). In this example, the capacity booster
cell uses similar mechanisms as used by the coverage cell to
determine if the capacity booster cell needs to be activated for UE
reasons. These may be configurable. These are in addition to
conventional configurations of average PRB usage. So, the capacity
booster cell does not deactivate simply based on average PRB load
thresholds as described above, but also based on individual UE
criteria which are described herein that the coverage cell also
uses, e.g., if the booster cell is already deactivated. In block
435, the EMS 405 acts to configure the coverage cell 106 with
certain exemplary metrics (e.g., a threshold for individual UE UL
data rate usage and duration, and/or power headroom margin
threshold). Other possible metrics are indicated in blocks 450 and
460, and block 435 may also configure thresholds for these other
metrics.
[0116] Blocks 415, 420, 425, and 430 illustrate a typical sequence
for a capacity booster cell 105 to place itself into an energy
saving state, e.g., wherein Tx and Rx in the transceiver 138 are
off or at least transmission and reception is not occurring using
the Tx and Rx. In block 415, the capacity booster cell 105
determines if low cell load is detected. In an example, a
determination is made there is low cell load in response to the
cell load falling below one or more thresholds for a configured
time duration as well as no individual UE needs require continued
activation of the nearby capacity booster cell. Exemplary
thresholds are described below. Such a load threshold could be
configured, e.g., in block 410. If a low cell load is not detected
in block 415 (block 415=No), the capacity booster cell 105
continues in block 415 (i.e., the capacity booster cell 105
continues to service connected UEs). If a low cell load is detected
in block 415 (block 415=Yes) and no individual UE needs require
continued activation of the nearby capacity booster cell, the
capacity booster cell 105 continues in block 420, where the
capacity booster cell 105 sends Handover (HO) Request messages
(Msg(s)) to the coverage cell 106 with a handover cause of Switch
Off Ongoing per 3GPP TS 36.423 for any connected UE. This causes
UEs connected to the capacity booster cell 105 to be handed over
and connected to the coverage cell 106. In typical scenarios, a UE
should connect to a strongest cell if idle or be handed over to a
cell based on existing radio resource measurements (which are
already defined in 3GPP TS 36.133) taken by the UE. If the UE is
within some distance from the capacity booster cell 105, generally
the booster cell's Tx signal is seen by UE as the strongest signal
(relative to the Tx signal of the coverage cell 106) based on,
e.g., RSRP and RSRQ level measurements. Where this is the case (Tx
of capacity booster cell 105 greater than Tx of coverage cell 106)
typically defines the coverage area for the capacity booster cell
105 and may also be used to define the coverage area of the
coverage cell 106.
[0117] The capacity booster cell 105 cooperates with the coverage
cell 106 to perform handovers of UEs connected to the capacity
booster cell 105 to the coverage cell 106 in block 425. In block
430, the capacity booster cell 105 sends neighbor cell(s) an eNB
Configuration (Config) Update Message (Msg) with a Deactivation
Indication IE and the capacity booster cell 105 enters an energy
savings state (e.g., carriers are deactivated, such as by turning
off the Rx, Tx of transceiver 138) and becomes dormant. In block
490, the capacity booster cell 105 updates the O&M system 191
(e.g., via the EMS 405) to indicate the booster cell is
deactivated. The capacity booster cell 105 is now dormant and in
the energy savings state.
[0118] In block 445, the coverage cell 106 receives the Handover
(HO) Request messages (Msgs) and the eNB Configuration (Config)
Update with the Deactivation Indication IE. In this manner, the
coverage cell 106 can determine the capacity booster cell 105 is
going to transition into an energy savings state and should not
hand the UE's back to cell 105. In an exemplary embodiment, the
coverage cell 106 determines (block 437) whether, for a selected UE
(or multiple UEs), the capacity booster cell 105, which is
currently in an energy saving state in this example, would have a
better performing radio frequency interface (Uu) connection with
the selected user equipment than the selected user equipment
currently has with the coverage cell 106. For instance, in block
450, an eNB 107 may be configured with certain QCI/QoS parameters
when a certain radio access bearer is set up to be used for a UE
user application. The eNB receives, for instance, an S1: INITIAL
CONTEXT SETUP REQUEST message or an S1: E-RAB SETUP REQUEST message
containing a E-RAB Level QoS Parameters IE which contains a QCI IE
indicating a GBR bearer (as defined in 3GPP TS 23.203 V0.1.1
(2005-10)). The following is from the 3GPP TS 36.413 tabular,
section 9.2.1.15, E-RAB Level QoS Parameters (which also states
"This IE defines the QoS to be applied to an E-RAB"):
TABLE-US-00001 IE type and Semantics IE/Group Name Presence Range
reference description E-RAB Level QoS Parameters >QCI M INTEGER
QoS Class Identifier (0 . . . 255) defined in TS 23.401 [11].
Coding specified in TS 23.203 [13]. >Allocation and M 9.2.1.60
Retention Priority >GBR QoS O 9.2.1.18 This IE applies to
Information GBR bearers only and shall be ignored otherwise.
[0119] This configuration may occur in block 450, and also in block
450, it is determined by the coverage cell 106 that a selected UE
E-RAB is configured with a QCl/QoS (e.g., as required for the UE),
which is not being efficiently met in terms of, e.g., individual UE
PRB usage and/or UE battery power usage and which implies that the
current radio frequency interface (e.g., Uu) connection (e.g., link
115-1 of FIG. 1) is not as good perhaps as a radio frequency
interface (e.g., Uu) connection (e.g., link 115-2 of FIG. 1) would
be if the UE is able to be handed into the capacity booster cell
105. Put differently, the quality of the radio frequency coverage
for the selected user application may be improved by having the
user equipment connect to the capacity booster cell 105 instead of
remaining connected to the coverage cell. Thus, particular E-RAB
configurations with particular QCI and QOS values (e.g., see
section 9.2.1.15 of 3GPP TS 36.413) may result in a capacity
booster cell not triggered to go dormant (see block 487, described
below) or to be reactivated (see blocks 470/475) if a UE is within
the coverage area of the capacity booster cell 105 and the capacity
booster cell 105 is dormant, regardless of the average cell load
(e.g., as determined using percent PRB usage) configured values for
ES given with conventional systems.
[0120] As another example, in block 455, the eNB 107 detects that
individual UE(s) meet certain criteria. Exemplary criteria are
shown in block 460. An eNB 107 may determine any one or more of the
following applies to a selected UE: 1) a UE has little power
headroom; 2) an UL bit rate metric for a UE exceeds a threshold; 3)
a UE requires high performance; 4) a UE MCS level meets certain
criteria, and 5) a UE has significant battery usage. These are
non-limiting and merely exemplary and other criteria may be used.
Each of these implies that the current radio frequency interface
(e.g., Uu) connection (e.g., link 115-1 of FIG. 1) is not nearly as
good perhaps as a radio frequency interface (e.g., Uu) connection
(e.g., link 115-2 of FIG. 1) would be if the UE is able to be
handed into the capacity booster cell 105. If one or more of the
criteria are not met (blocks 450 and 455=No), the coverage cell 106
proceeds to block 450. That is, connected UEs are continued to be
serviced. If one or more of the criteria are met (one of blocks 450
or 455=Yes), the coverage cell 106 proceeds to block 465.
[0121] In block 465, it is determined if the UE(s) is in or moving
into coverage area of the capacity booster cell 105. As stated
above, there are a number of techniques useful to detect if a UE
resides in the coverage area of a capacity booster cell 105: 1)
internal mechanisms of the coverage eNB, e.g. TA/AOA mechanisms; 2)
probing, where the coverage cell activates pico cell(s) for a brief
time period to obtain UE measurements; 3) a pico cell is in a
discontinuous carrier activation mode; 4) UE reports based, e.g.,
on satellite location systems; 5) Minimization of drive testing
(MDT); 6) UE measurement reports of other cells on the same and/or
different; 7) requests to a positioning server; and 8) combinations
of the above. If location of UE(s) is not certain, the coverage
cell 106 may send the X2:Cell Activation Request message (block
470) to multiple capacity booster cells, one of which the UE might
be able to connect to as an original cell (per normal HO triggers).
Alternately, the capacity booster cell(s) may be placed in a
discontinuous transmission mode (e.g., discontinuous carrier
activation mode) to enable UE positioning. Such a mode is described
in U.S. patent Ser. No. XX/XXX,XXX, entitled "BASE STATION POWER
SAVINGS AND CONTROL THEREOF", by inventors Michael Bach and Robert
Nikides.
[0122] If the UE(s) is not in or moving into the coverage area of
the capacity booster cell 105 (block 465=No), the coverage cell 106
proceeds to block 450. If the UE(s) is in or moving into the
coverage area of the capacity booster cell 105 (block 465=Yes), the
coverage cell 106 sends (block 470) a Cell Activation Request
message (Msg) to the capacity booster cell 105. This message
includes, e.g., an instruction for the capacity booster cell 105 to
transition from the energy saving state to an active state (e.g.,
Tx and Rx fully on). In block 475, the coverage cell 106 also sends
HO Request messages (msg(s)) with a "don't go dormant" IE for the
selected (e.g., "high value") UE(s) (e.g., or to indicate the UE
has a high value user application). Responsive to the Cell
Activation Request message, in block 480, the capacity booster cell
105 transitions from the energy saving state to an active state
(e.g., Tx and Rx fully on). Responsive to the HO Request messages
with a "don't go dormant" IE for the selected (e.g., "high value")
UE(s), the capacity booster cell 105 in block 480 remains in an
active state at least until the high value UE(s) or UE user
application(s) are no longer attached to the capacity booster cell
105. In an example, the requested application should result in a
MME (mobility management entity) requesting the eNB to set up an
E-RAB (associated with particular QCI/QOS values besides IP
addresses, etc., for that type application's needs) to be used for
that user application. If the user closes out the user application,
the closure should result in the MME requesting the eNB to release
the E-RAB for the user application. In block 485, the capacity
booster cell 105 updates the O&M system 191 (e.g., the EMS 405)
to indicate the booster cell is activated. Once the high value
UE(s) are no longer attached to the capacity booster cell 105 or
released the E-RAB(s) associated high value user application, the
capacity booster cell 105 may return to block 415 and may return to
the energy savings state.
[0123] Regarding the "don't go dormant" IE referred to in block 475
of FIG. 4, FIG. 5 is a table representing a number of IEs and
includes a "Don't go Dormant" IE useful for an exemplary embodiment
of the instant invention. The table (without the Don't go Dormant
IE information) is shown in section 9.1.1.1 (HANDOVER REQUEST) of
3GPP TS 36.423 V11.0.0 (2012-03). The Don't go Dormant IE is a new
IE instruction used to inform the capacity booster cell 105 the
cell should not go dormant (e.g., into an energy saving state)
while the corresponding UE is connected to the capacity booster
cell 105. It is noted this instruction also means the cell
receiving this UE and corresponding IE should not hand the UE back
to the coverage cell 106 and go dormant due to low overall load.
The Don't go Dormant IE would be described in this example in
section 9.2.x.x (i.e., a future section) of TS 36.423. The sections
listed in FIG. 5 are from TS 36.423, the presence of M indicates
the IE/Group is mandatory, and O indicates the IE/Group is
optional.
[0124] It is noted that the description above with respect to FIG.
4 indicates that the capacity booster cell 105 is in an energy
saving state when block 475 is performed. However, that need not be
the case. In other words, the capacity booster cell 105 may be in
an active state and blocks 437, 450, 455, and 465 would still be
performed by the coverage cell 106. In this example, block 470
would not be performed (i.e., because the capacity booster cell 105
is not in the energy saving state), but block 475 would be
performed. This allows the coverage cell 106 to instruct an active
capacity booster cell 105 to remain active for high value UE(s). In
another example, the Cell Activation Request message in block 470
is modified and the HO Request message in block 475 may not include
the Don't Go Dormant IE. For instance, in block 470, the coverage
cell 106 sends an optional IE (called "Enable for UE" herein) added
in the X2:Cell Activation Request Message in block 470 that
indicates the receiving cell should be Activated (e.g., switch On)
and remain activated for at least the length of the connection for
the UE(s) which is (are) identified by the Enable for UE IE. FIG. 6
illustrates a table of possible elements in a Cell Activation
Request message in accordance with an exemplary embodiment. This
figure is a representation (without the Enable for UE) of section
9.1.2.20, CELL ACTIVATION REQUEST, of TS 36.423. This message is
sent by an eNB to a peer eNB to request a previously switched-off
cell/s to be re-activated. The direction is from eNB.sub.1 (i.e.,
coverage cell 106) to eNB.sub.2 (i.e., capacity booster cell 105).
A new information element is Enable for UE, which is optional and
is described in section 9.2.x.y (e.g., a to be added section),
which is partially shown in FIG. 7. The Enable for UE IE requests
that the receiving eNB activate the cell and provide service to the
identified UE IDs, which are to be handed over to the receiving
eNB. FIG. 7 illustrates two tables for an Enable for UE IE. The
first (topmost) table describes elements of the IE, including eNB
UE X2AP ID (e.g., each of which is a unique ID for a UE) and a
second table describing a maxnoofUEs range. The maximum number of
UEs (maxnoofUEs) is 256 in this example.
[0125] The eNB receiving the X2:Cell Activation Request Message
with this new IE should remain activated for the given UE(s)
regardless of configured switch off threshold(s) (e.g.,
esActivationOriginalCellLoadParameters, see below). The capacity
booster eNB 108 may be expected to go dormant again if load is not
above a switch-off threshold when the UE(s) disconnects and, e.g.,
after a suitable time duration and if no individual UE needs
require continued activation of the capacity booster cell.
[0126] In another example, the capacity booster cell 105 can make a
determination in block 487 as to whether individual UE(s)/user
application(s) metrics meet certain criteria. As noted above, the
capacity booster cell does not deactivate simply based on average
PRB load thresholds as described above, but also based on
individual UE criteria which are described herein that the coverage
cell also uses, e.g., if the booster cell is already deactivated.
The criteria may include the criteria described in relation to
blocks 450, 455, and 460, along with other criteria described
herein. In one example, block 487 performs an opposite operation as
to what is in block 437: the eNB 108 determines the eNB 108 could
support a better performance Uu connection as compared to a Uu
connection with a coverage eNB 107. Responsive to a determination
the individual UE(s)/application(s) meet the certain criteria, the
booster cell in block 480 remains activated at least until high
value UE(s)/user application(s) is/are no longer connected.
[0127] Regarding metrics in block 410 used to configure the
capacity booster cell 105 or in block 435 to configure the coverage
cell 106, an addition may be made to 3GPP TS 32.522 for the
following exemplary additional original cell load threshold(s)
based on individual UE PRB usage. One such attribute is
esActivationOriginalCellUELoadParameters. This attribute indicates
the traffic load threshold for a UE used by distributed ES
algorithms to allow a cell to enter the energySaving state. A
corresponding threshold is an integer between 0.100 (Percentage of
UL PRB usage, see 3GPP TS 36.314). This attribute may also be based
on a UE transmission cost metric. Duration time may also be added
as well. For instance, time duration associated with load threshold
for may be used as is currently specified along with overall load.
See the following example paragraph definition from 3GPP TS 32.522
(part of table 5.5.1.1):
TABLE-US-00002 esActivationOriginalCellLoadParameters This
attribute indicates the traffic load threshold and Threshold:
Integer 0 . . . 100 (Percentage the time duration, which are used
by distributed ES of PRB usage, see 3GPP TS 36.314 [13]) algorithms
to allow a cell to enter the energySaving TimeDuration: Integer (in
unit of state. The time duration indicates how long the load
seconds) needs to have been below the threshold.
[0128] These metrics may be used in block 455 or 487. Furthermore,
an addition may be made to TS 32.522 to add an additional candidate
cell load threshold based on individual UE PRB usage.
[0129] Another example is the attribute
esDeactivationCandidateCellUELoadParameters. This attribute
indicates the traffic load threshold for a UE used by distributed
ES algorithms to allow a cell to leave the energySaving state. The
threshold is an Integer between 0.100 (Percentage of UL PRB usage,
see 3GPP TS 36.314). This attribute may also be based on a bit rate
metric.
[0130] If the coverage cell 106 detects (block 455 of FIG. 4) a UE
has a high transmission cost, e.g. surpasses the
esDeactivationCandidateCellUELoadParameters or transmission cost
metric, and the UE could connect to a capacity booster cell 105
(with normal HO triggers when active), but the capacity booster
cell 105 is in the dormant state, then the coverage cell 106 sends
an X2:Cell Activation Request message to the dormant cell and
includes a new IE indicating UE(s) that cell should service these
UEs (as described above in reference to FIGS. 6 and 7) and remain
in an active state while doing so.
[0131] UE location (as noted above) may be known via UE reports
based on, e.g., satellite location systems which might be mapped to
known dormant cell coverage, based on MDT reports, based on eNB
based positioning methods e.g. based on TA and AOA (angle of
arrival), or any other suitable technique. If location of UE(s) is
not certain, the coverage cell 106 may send the X2:Cell Activation
message to multiple capacity booster cells, one of which the UE
might be able to connect to as an original cell (per normal HO
triggers). Alternately, the capacity booster cell(s) may be placed
in a discontinuous transmission mode to enable UE positioning.
[0132] Checking for UE load above the
esDeactivationCandidateCellUELoadParameters may be triggered by a
low value for the UE reported power headroom. The power headroom
(PH), expressed in dB, is defined as the difference between the
configured maximum UE output power (PCMAX), which is defined in
section 6.2.5 in TS 36.101 and the estimated power for PUSCH
transmission according to section 5.1.1.1 in 3GPP TS 36.213.
[0133] Determination of the UE transmission cost in a coverage cell
106 may be based on a UE metric composed of one or more of the
following parameters: 1) Power Headroom (PH): low average value, 2)
Spatial multiplexing: No, i.e. a single spatial layer 3) Bit rate:
high average value, 4) MCS: low average value. Actual metrics may
be implementation specific. These may be implemented, e.g., by
blocks 460 and 455 of FIG. 4 above. Additional information
regarding these parameters is provided below. The following
information is from 3GPP TS 36.321 V10.5.0 (2012-03). In section
6.1.3.6 (Power Headroom MAC Control Element), it states the
following:
[0134] "Power Headroom MAC control element is identified by a MAC
PDU subheader with LCID as specified in table 6.2.1-2. It has a
fixed size and consists of a single octet defined as follows (FIG.
6.1.3.6-1): [0135] R: reserved bit, set to "0"; [0136] Power
Headroom (PH): this field indicates the power headroom level. The
length of the field is 6 bits. The reported PH and the
corresponding power headroom levels are shown in Table 6.1.3.6-1
below (the corresponding measured values in dB can be found in
subclause 9.1.8.4 of [9])."
[0137] The following table is table 6.1.3.6-1, Power Headroom
levels for PHR (power headroom report), from 3GPP TS 36.321:
TABLE-US-00003 PH Power Headroom Level 0 POWER_HEADROOM_0 1
POWER_HEADROOM_1 2 POWER_HEADROOM_2 3 POWER_HEADROOM_3 . . . . . .
60 POWER_HEADROOM_60 61 POWER_HEADROOM_61 62 POWER_HEADROOM_62 63
POWER_HEADROOM_63
[0138] The following information is from 3GPP TS 36.133 V10.5.0
(2011-12). In section 9.1.8.4, Report Mapping, it states the
following: "The power headroom reporting range is from -23 . . .
+40 dB. Table 9.1.8.4-1 defines the report mapping." Table
9.1.8.4-1, Power headroom report mapping, is shown below:
TABLE-US-00004 Reported value Measured quantity value (dB)
POWER_HEADROOM_0 -23 .ltoreq. PH < -22 POWER_HEADROOM_1 -22
.ltoreq. PH < -21 POWER_HEADROOM_2 -21 .ltoreq. PH < -20
POWER_HEADROOM_3 -20 .ltoreq. PH < -19 POWER_HEADROOM_4 -19
.ltoreq. PH < -18 POWER_HEADROOM_5 -18 .ltoreq. PH < -17 . .
. . . . POWER_HEADROOM_57 34 .ltoreq. PH < 35 POWER_HEADROOM_58
35 .ltoreq. PH < 36 POWER_HEADROOM_59 36 .ltoreq. PH < 37
POWER_HEADROOM_60 37 .ltoreq. PH < 38 POWER_HEADROOM_61 38
.ltoreq. PH < 39 POWER_HEADROOM_62 39 .ltoreq. PH < 40
POWER_HEADROOM_63 PH .gtoreq. 40
[0139] So low reported values of power headroom indicate the UE is
transmitting at its maximum power. Thus, certain thresholds for
average UE reported Power Headroom level for a time duration may
result in a capacity booster cell 105 triggered not to go dormant
(see, e.g., blocks 455/460/465/470/475, 487, and 480) or to be
reactivated if a particular UE is within the coverage area of the
capacity booster cell 105, regardless of the current cell load
(e.g., as determined using percent PRB usage) configured values for
ES. This may be combined with an average UE bit rate usage.
[0140] High bit rate user applications may be indicated via the Bit
Rate IE present in bearer setup messages received by the eNB via
the S1-AP interface as given in 3GPP TS 36.413 V10.4.0 (2011-12)
per the following sections. In section 9.2.1.18, GBR QoS
Information, the following is stated: "This IE indicates the
maximum and guaranteed bit rates of a GBR bearer for downlink and
uplink." The following table is also from section 9.2.1.18.
TABLE-US-00005 IE type IE/Group and Name Presence Range reference
Semantics description E-RAB M Bit Rate Desc.: This IE indicates
Maximum 9.2.1.19 the maximum downlink Bit Rate E-RAB Bit Rate as
Downlink specified in TS 23.401 [11] for this bearer. E-RAB M Bit
Rate Desc.: This IE indicates Maximum 9.2.1.19 the maximum uplink
Bit Rate E-RAB Bit Rate as specified in TS 23.401 Uplink [11] for
this bearer. E-RAB M Bit Rate Desc.: This IE indicates Guaranteed
9.2.1.19 the downlink guaranteed Bit Rate E-RAB Bit Rate as
Downlink specified in TS 23.401 [11] (provided that there is data
to deliver) for this bearer. E-RAB M Bit Rate Desc.: This IE
indicates Guaranteed 9.2.1.19 the uplink guaranteed Bit Rate E-RAB
Bit Rate as Uplink specified in TS 23.401 [11] (provided that there
is data to deliver) for this bearer
[0141] In section 9.2.1.19, Bit Rate, it states the following:
"This IE indicates the number of bits delivered by E-UTRAN in UL or
to E-UTRAN in DL within a period of time, divided by the duration
of the period. It is used, for example, to indicate the maximum or
guaranteed bit rate for a GBR bearer, or an aggregated maximum bit
rate." The following table is from section 9.2.1.19.
TABLE-US-00006 IE/ IE type and Semantics Group Name Presence Range
reference description Bit Rate INTEGER The unit is: (0 . . . bit/s
10,000,000,000)
[0142] MCS indices are defined in 3GPP TS 36.213 V10.4.0 (2011-12),
tables 7.1.7.1-1 and 8.6.1-1, and determine UE throughput based on
the modulation order and redundancy to be used with the
transmission. Low MCS values indicate the transmission requires
lower modulation orders and more redundancy which is associated
with higher propagation losses over the wireless link 115-1.
[0143] The techniques of activating a dormant cell to handle a UE
requiring high Uu perf may also be triggered (e.g., block 450 in
FIG. 4) by the coverage eNB 107 receiving particular QCI value(s)
in the SlAP bearer setup procedures (see TS 36.413) for a UE, e.g.,
QCI values for user applications requiring high bandwidth, low
latency such as real time gaming (QCI=3) and/or live streaming
video (QCI=2). This may be combined with large values for GBR QoS
information, in particular for the IE supplied in the bearer setups
that indicates the uplink guaranteed E-RAB Bit Rate as specified in
3GPP TS 23.401. FIG. 8 is a table of E-RAB Level QoS Parameters
from section 9.2.1.15 of 3GPP TS 36.413 V10.4.0 (2011-12).
[0144] Alternately or in addition, a new QCI value or new 36.413
SlAP IE associated with E-RAB setups can be defined to indicate to
an eNB that the UE should be connected over the Uu interface with a
high performance link in order to minimize UE battery consumption.
The new indication to the dormant cell to support a specified UE
regardless of overall cell load may as an addition or alternative
include a new IE in HANDOVER REQUEST message. The capacity booster
cell 105 may also make corresponding checks as described herein for
the coverage cell before going dormant. The EMS 405 may configure,
e.g., via an attribute, whether the techniques described herein are
to be used by an eNB or not. Thus, certain average UE channel
quality indication (CQI) indices thresholds for a time duration may
result in a capacity booster cell not triggered to go dormant or to
be reactivated if a UE is within its coverage area regardless of
the average cell load (e.g., as determined using percent PRB usage)
configured values for ES given per conventional systems. This may
be combined with an average UE bit rate usage. CQI is reported by
UE. CQI is similar to MCS and used to generate the MCS used. CQI is
given as a table of 16 values. See 3GPP TS 36.213 Section 7.2.3,
table 7.2.3-1.
[0145] Values of QOS, MCS and bit rate are per downlink and uplink.
Spatial multiplexing is also possible in the uplink as well as the
downlink. While uplink may be more critical, at least with respect
to UE battery life, the capacity booster cell may be triggered not
to go dormant or reactivated based on either or both of UE UL and
DL threshold values. These parameter trigger values/thresholds are
likely different for the booster cell than for the coverage cell.
For instance, a capacity booster cell may not go dormant if a UE
has one or more of significant tx power headroom indicated by UE
reports of high PH values (i.e., UE transmitting at low power),
high rank (multiple spatial layers possible), high MCS, and/or high
reported channel quality index (CQI). Meanwhile, a coverage cell
seeks to reactivate a booster cell for a UE that is connected to
the coverage cell which e.g. experiences low power headroom (i.e.,
transmitting at high power), low rank (one layer, no spatial
multiplexing), low MCS values, and/or low reported channel quality
index (CQI). The values used for these by the capacity booster cell
may be configured.
[0146] As yet another set of examples, if a UE has a high degree of
spatial multiplexing available, i.e., the ability to send data on
separate antenna paths via different layers as indicated by its
average Rank Indicator (RI) for MIMO for a time duration, this may
result in the capacity booster cell triggered not to go dormant
(e.g., or not triggered to go dormant) or to be reactivated if the
UE is within its coverage area regardless of the average cell load
(e.g., as determined by percent PRB usage) configured values for
ES. The UE reports its recommended RI to eNB. Therefore, certain
thresholds for a certain average UE RI values for a time duration
may result in a capacity booster cell triggered not to go dormant
(e.g., or not triggered to go dormant) or to be reactivated if a UE
is within the coverage area of the capacity booster cell 105,
possibly combined with the coverage cell having knowledge that a
activated capacity booster cell typically supports multiple spatial
layers, regardless of the average cell load configured values for
ES. This may be combined with an average UE bit rate usage.
[0147] FIG. 9 is a logic flow diagram illustrating the operation of
a method, and a result of execution of computer program
instructions embodied on a computer readable memory, in accordance
with the exemplary embodiments of this invention. The operations
performed in these blocks are performed, e.g., by a base station
such as the eNB 107 that forms a coverage cell 106. In block 910,
the base station determines, at a first cell and for a selected
user equipment, a second cell would have a better performing radio
frequency interface connection with the selected user equipment
than the selected user equipment currently has with the first cell.
The first cell can provide radio frequency coverage for the second
cell That is, technically, the UE need not be connected to second
cell, as the first cell can provide radio frequency coverage for
the UE over the coverage area of the second cell. That is, when the
second cell is in an energy saving state, the first cell will
provide (assuming the first cell is also not in the energy saving
state) radio frequency coverage for the second cell. If the second
cell is in an active state, the first cell can provide radio
frequency coverage for the second cell, but for individual UEs may
or may not provide the coverage (e.g., UEs that quickly move
through the coverage area of the second cell may not be handed over
from the first cell to the second cell). In block 920, the base
station sends to the second cell one or more messages comprising
one or more instructions the second cell should not enter or be in
an energy saving state at least while the selected user equipment
or a selected user application on the user equipment is connected
to the second cell. The sending is responsive to a determination
the second cell would have a better performing radio frequency
interface connection with the selected user equipment than the
selected user equipment currently has with the first cell.
[0148] FIG. 10 is a logic flow diagram illustrating the operation
of a method, and a result of execution of computer program
instructions embodied on a computer readable memory, in accordance
with the exemplary embodiments of this invention. The operations
performed in these blocks are performed, e.g., by a base station
such as eNB 108 that forms a capacity booster cell 105. In block
1010, the base station determines a cell should not enter an energy
saving state at least while a selected user equipment is connected
to the cell. In block 1020, the base station causes the cell to not
enter the energy saving state at least while the selected user
equipment is connected to the cell.
[0149] Embodiments of the present invention may be implemented in
software (executed by one or more processors), hardware (e.g., an
application specific integrated circuit), or a combination of
software and hardware. In an example embodiment, the software
(e.g., application logic, an instruction set) is maintained on any
one of various conventional computer-readable media. In the context
of this document, a "computer-readable medium" may be any media or
means that can contain, store, communicate, propagate or transport
the instructions for use by or in connection with an instruction
execution system, apparatus, or device, such as a computer, with
one example of a computer described and depicted, e.g., in FIG. 2.
A computer-readable medium may comprise a computer-readable storage
medium (e.g., memory 125, 155, 195 or other device) that may be any
media or means that can contain or store the instructions for use
by or in connection with an instruction execution system,
apparatus, or device, such as a computer.
[0150] If desired, the different functions discussed herein may be
performed in a different order and/or concurrently with each other.
Furthermore, if desired, one or more of the above-described
functions may be optional or may be combined.
[0151] Although various aspects of the invention are set out in the
independent claims, other aspects of the invention comprise other
combinations of features from the described embodiments and/or the
dependent claims with the features of the independent claims, and
not solely the combinations explicitly set out in the claims.
[0152] It is also noted herein that while the above describes
example embodiments of the invention, these descriptions should not
be viewed in a limiting sense. Rather, there are several variations
and modifications which may be made without departing from the
scope of the present invention as defined in the appended
claims.
* * * * *